Separated from the Doctor, Clara discovers a new menace from another dimension. But how do you hide when even the walls are no protection? With people to save and the Doctor trapped, Clara comes up against an enemy that exists beyond human perception.

Synopsis Source: BBC America website schedule listing

Broadcast Source: BBC America

Ratings Information:

The episode achieved a 0.754m Live+SD rating for the evening on cable, with a 0.30 Adult 18-49 Rating. It was the 19th original show (>100 with ties) in the chart [source: ShowBuzz Daily / TV By The Numbers ]